Topaz gemstones. This silicate mineral (aluminium silicate fluoride hydroxide) can range in colour from golden brown to yellow. A blue variety is often confused with aquamarine,although it does not occur in nature. Topaz can be polished in a variety of shapes: oval (centre left),cushion cut (far right) and opposed bar (across bottom) are seen. It is rated as 8 out of 10 on the Mohs hardness scale,with diamond rated as 10 | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Lawry, Lawrence |
Taille de l’image : | 4209 px × 3452 px |
Model Release : | Non requis |
Property Release : | Non requis |
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